This has been described thoroughly in our chapter on etched work.
III
INTAGLIO AND RELIEF WITH SEVERAL PLATES
As already shown, intaglio and relief can be printed on one stone. Therefore it is evident that the two methods can be utilized still better for several plates, for instance, printing on an etched design with one or more plates that are tinted in relief, or by printing over a crayon or pen design in relief a tone plate in aquatint in intaglio.
How to do this has been explained in the descriptions of relief and intaglio methods.
IV
TRANSFORMING RELIEF INTO INTAGLIO AND VICE VERSA
This is, so to speak, the test of a good lithographer, as it is the most difficult of all methods, and demands exact knowledge of all manipulations. I will try to explain it with a few examples.
EXAMPLE I
To etch a transfer into intaglio
Prepare a finely ground plate with phosphoric acid and gum, wash very well with water, and let it dry. Now transfer to it a design made with soft ink or crayon, or a fresh copper-plate impression. Let the stone rest for a few hours, that the fatty colors may take hold well. Coat it with clean gum water, and with a rag dipped into acid-proof ink try to rub about as much color on the design as appears to be required to make it withstand some etching. This etching is done with pure aquafortis which in addition has a little alum mixed with it. Etch only enough to eat away the uppermost parts of the prepared surface that have not been permeated with fat. Pour clean water over the whole stone and coat it with strong soap-water that is permitted to dry on it. Finally, clean away the soap with oil of turpentine. Ink-in with acid-proof color which will color the whole stone. Now as soon as it is wiped gently with a rag dipped in gum solution and weak phosphoric acid, the whole design will appear in white as if it had been made with preparing-ink. If the stone is inked now with acid-proof ink and treated exactly as instructed in the article on the use of preparing-ink, the design that was in relief originally will be found in intaglio.
This process is capable of great perfection and can produce true masterpieces especially if the stone is treated finally with the engraving tool.